| Project/Area Number |
03044051
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | University of Tokyo |
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Principal Investigator |
SHIMIZU Hiroshi Faculty of Pharmaceutical Sciences, University of Tokyo, 薬学部, 教授 (30037577)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Yoko Faculty of Pharmaceutical Sciences, University of Tokyo, 薬学部, 助手 (00158122)
YANO Masafumi Faculty of Pharmaceutical Sciences, University of Tokyo, 薬学部, 助教授 (80119635)
KOERNER Edgar Ilmenau Institute of Technology (Germany), 教授
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| Project Period (FY) |
1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1991: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | Hippocampus / Neocortex / Memory / theta rhythm / phase-locked loop / synchronization / neural network / dynamical coherence |
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| Research Abstract |
The issue of cortico-hippocampal interplay is a key point for the understanding of not only the mechanism for the recognition but also the memory. One of characteristic points of the hippocampal activities is the appearance of highly coherent rhythmicity by the frequency of several heltz, called theta rhythm. The change of theta rhythm in hippocampus is known to have correlation with the change of behavior or psychological states. Theta rhythm appears not only in the hyppocampus but also the association cortex connecting with the hippocampus. On the other hand neocortex has its own characteristic rhythms depending on the external signals. It was recently reported as experimental evidences in cat visual cortex, while it had been theoretically predicted that the presence of rhythmic activities and the significance of their synchronization for encoding of the figure separating ground as desynchronized activities. The aim of the present research was to investigate the generation of dynamical coherence between the hippocampal system and the cortical part as a process of information integration.
The modelling of hippocampal network was investigated mainly by the group of Dr. Koerner. The hippocampus was modelled as a nonspecific controller, which stabilizes and amplifies the units in phase and suppresses others. The model of cortical information processing was mainly investigated by the group of Dr. Shimizu. The principle of dynamical coherence was applied to the visual pattern recognition. The model of cortico-hippocampal network was extensively designed ny connecting the model of hippocampal network and the model for the pattern recognition. The problem what should be memorized under various input of visual scene is now under investigation.
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